1. The Field of the Invention
In one aspect, the present invention is directed to devices for holding and dispensing dental compositions. More particularly, in one aspect, the invention is directed to containers for holding and dispensing dental compositions having a given shelf-life after which the composition should either be used up or discarded. For example, many multi-part dental compositions require mixing of two separate components, the mixed composition having a particular shelf-life, after which time the mixed composition should be used up or discarded. Another aspect of the invention is related to methods for mixing such compositions and indicating shelf-life of the resulting compositions.
2. The Relevant Technology
Many modern formulations are packaged in two initially separate parts, often known as A and B components. Upon mixing, the A and B components form a mixed composition having a particular viable shelf-life, after which the composition should be used up or discarded. In the dental field, for example, several such formulations include two-part dental primers, peroxide and other two-part bleaching compositions, and disinfecting solutions.
It can be difficult for a dental practitioner to determine whether the shelf-life of a formulation has expired, or how much of the formulation's shelf-life remains. This difficulty can be further complicated in some instances where the shelf-life of a given formulation may depend on the environment in which the formulation is stored. For example, many formulations may have an extended shelf-life if stored in a refrigerated environment as compared to the shelf-life when stored at room temperature.
Furthermore, when mixing a two-part composition it is necessary to measure needed amounts of each component. In addition to being tedious, even small variations in measurement of one component relative to another component may drastically affect the actual shelf-life of the mixed composition because of errors in the mixing ratio of the components.
It would be an advantage to provide a container system for use with such a formulation that would allow the user to quickly and easily determine how much time remains of the shelf-life of a given formulation. It would be a further advantage if such a system could account for variability in shelf-life due to changes in the formulation storage environment. It would be a further advantage to provide a simple method that would indicate remaining shelf-life of a composition, and that would eliminate variability in actual shelf-life due to errors in measuring needed quantities of the components.